September 2017doc.: IEEE 802.11-17/1389r3
IEEE P802.11
Wireless LANs
Date: 2017-09-11
Author(s):
Name / Affiliation / Address / Phone / email
Joseph Levy / InterDigital, Inc. / 2 Huntington Quadrangle,
4th Floor, South wing
Melville, NY 11747 / +1 631 662 4139 /
Donald Eastlake / Huawei Technologies / 155 Beaver Street, Milford, MA 01757 USA / +1-508-333-2270 /
4.3.27.4 GLK Service Sets
4.3.27.4.1 Provision of the MAC service
MAC service data unit (MSDU) delivery services in an IEEE Std 802.1Q network can be supported by the 802.1AC MAC service. GLK STAs coordinate with an 802.1AC compliant GLK convergence function, to provide access to the WM via one or more Internal Sublayer Service SAPs. The routing of all MSDUs, that are provided by an 802.1Q relay entity, via GLK STAs is controlled by the routing protocols of the IEEE Std 802.1Q network that the GLK STA is attached to. This enables the routing protocols to use all ofall the WM general links available to the GLK STA, including any direct links that are available.
MSDU delivery services provided at the MAC-SAP to the LLC layer provide routing of all MSDUs. This service can use the WM, via general links provided by GLK STAs, to provide this service.
4.3.27.4.2 GLK IBSS and PBSS
A GLK IBSS or GLK PBSS can provide access to the WM via general links that are suitable for use in an IEEE Std 802.1Q network. Figure 4-13a (Example of GLK IBSS or PBSS) shows an example of a GLK IBSS involving three GLK non-AP STAs. Each participating STA provides the MAC servicesat the MS-SAP, with the inclusion of a station vector that is then mapped to one or more Internal Sublayer Service SAPs (ISSs) by the 802.1AC GLK Convergence Function. Three general links are shown that connect three pairs of Internal Sublayer Service SAPs in a point to point manner. Each of the Internal Sublayer Service SAPs is then mapped to either an Enhanced Internal Sublayer Service (EISS) SAP or MAC-SAP, by the 802.1Q Media Independent Function or the Internal Sublayer Service to MAC-SAP Function, respectively. The EISS SAP provides EISS services to the MAC relay entity of a VLAN bridge component (802.1Q MAC Relay Entity). The MAC-SAP provides services to the LLC Sublayer.
A difference from non-GLK AP’s 802.11 link, that can only be connected to an Internal Sublayer Service SAP via a DS and portal, is that either or both Internal Sublayer Service SAPs could directly connect to an IEEE Std 802.1Q bridge.
For example, each of the STAs and associatedattached bridges (including the 802.1Q MAC Relay Entities) shown could be at the top of a rack in a data center to provide inter-rack connectivity. with the STA providing, via the Internal Sublayer Service SAP, access to another STA and such other STA's associated bridge. A difference from non-GLK 802.11 is that either or both of the Internal Sublayer Service SAPs could be connected to an IEEE Std 802.1Q bridge or network providing IEEE Std 802.1Q service that, in turn could be connected to one or more end stations. The two Internal Sublayer Service SAPs shown could even be safely connected to the same IEEE Std 802.1Q network, since such a network provides protection from loops.
Also, shown in the figure is the possibility to provide a point to point link between two LLC Sublayer entities that are each attached to a GLK non-AP STA. For example, this link could allow a computer associated with a GLK STA to directly connect to a network attached storage device associated[LJ1] with a GLK STA.
Note: IEEE Std 802.11 does not specify the details of the 802.1AC GLK convergence Function, the 802.1Q Media Independent Function, the Internal Sublayer Service to MAC-SAP Function, the 802.1Q MAC Relay Entity, and the LLC Sublayer. These entities are specified in other document such as: IEEE Std 802.1AC™-2016 (Media Access Control (MAC) Service Definition) and IEEE Std 802.1Qbz™-2016 (Bridges and Bridged Networks — Amendment 27: Enhancements to Bridging of 802.11 Media). These entities are shown with dashed outlines in the figure. Entities that IEEE Std 802.11 does specify are shown with solid outlines and are within the box labelled 802.11 GLK IBSS/PBSS.
Figure 4-13a—Example of GLK IBSS or PBSS
A GLK PBSS similarly provides one or more linked instances of the MAC service.
4.3.27.4.3 Infrastructure BSS with general links
A GLK infrastructure BSS can provide access to the WM via general links that are suitable for use in an IEEE Std 802.1Q network. Figure 4-13b (Example of infrastructure BSS with general links) shows an example of a GLK infrastructure BSS with three GLK non-AP STAs and one GLK AP. Each participating STA provides MAC services at the MS-SAP, with the inclusion of a station vector that is then mapped to one or more Internal Sublayer Service SAPs by the 802.1AC GLK Convergence Function. Four general links are shown that connect four pairs of Internal Sublayer Service SAPs in a point-to-point manner. Each of the Internal Sublayer Service SAPs is then mapped to either an EISS SAP or a MAC-SAP, by the 802.1Q Media Independent Function or the Internal Sublayer Service to MAC-SAP Function, respectively. The EISS SAP provides EISS services to the MAC relay entity of a VLAN bridge component (802.1Q MAC Relay Entity). The MAC-SAP provides services to the LLC Sublayer.
An example infrastructure BSS with general links is shown in Figure 4-13b (Infrastructure BSS with general links). The MAC service to the bridge ports is provided via the Internal Sublayer Service SAPs shown. These multiple Internal Sublayer Service SAPs are logical entities implemented by a GLK convergence function.
Although transmissions by an AP are typically received by all STAs associated with that AP, the service provided by a GLK infrastructure BSS might be considered as separate point-to-point links between the corresponding Internal Sublayer Service SAPs (provided by the GLK AP and GLK convergence function) and each associated GLK STA. Provisioning of such apparent point-to-point links is natural for MPDUs with an individually addressed RA. In order to provide such apparent point-to-point links for group addressed frames the GLK AP can transmits them so that they are accepted by a subset of the associated GLK STAs. Such selective transmission can be provided through the GLK SYNRA addressing facility (see 4.3.27.3 (Selective reception of group addressed frames)) or by serial unicast.
Three types of example general links are shown in the Figure 4-13b (Example of infrastructure BSS with general links):
- The first type is an infrastructure general link that connects a non-AP GLK STA attached bridge port of an (802.1Q MAC Relay Entity) with an GLK AP attached bridge (there are two of these general links shown in the figure). These links could be used to enhance the reliability and routing options of a IEEE Std. 802.1Q compliant LAN by providing redundant wireless links between the bridges in the LAN.
- The second type is a non-AP GLK STA to non-AP GLK STA link that connects the STAs’ attached bridges (802.1Q MAC Relay Entities), this type of general link is similar to the IBSS or PBSS STA to STA link.
- The third type of general link is a “leaf-node” type of general link that connects entities in the LLC layer attached to a non-AP GLK STA via a general link and an IEEE Std 802.1Q bridge attached to the GLK AP to other entity available via the IEEE Std 802.1Q network attached to the GLK AP. Such a general link could provide a connection between a network printer attached[LJ2] to the LAN and a computer attached to the non-AP GLK STA.
Note: IEEE Std 802.11 does not specify the details of the 802.1AC GLK convergence Function, the 802.1Q Media Independent Function, the Internal Sublayer Service to MAC-SAP Function, the 802.1Q MAC Relay Entity, and the LLC Sublayer. These entities are specified in other document such as: IEEE Std 802.1AC™-2016 (2016 (Media Access Control (MAC) Service Definition) and IEEE Std 802.1Qbz™-2016 (Bridges and Bridged Networks — Amendment: 27 Enhancements to Bridging of 802.11 Media). These entities are shown with dashed outlines in the figure. Entities that IEEE Std 802.11 does specify are shown with solid outlines and are with in the box labelled 802.11 BSS.
Figure 4-13b—Example of infrastructure BSS with general links
4.3.27.4.4 Infrastructure BSSs with general links and in the presence of an ESS
BSSs that support general links can be components of an extended form of network by using the general links within an IEEE Std 802.1Q bridged network., for example as shown in the middle and left of Figure 4-13c (Example of ESS with general links). In such a bridged network, the concept of the DS in a non-GLK ESS is replaced by the other components of the IEEE Std 802.1Q network. However, such a GLK topology is more general than the non-GLK infrastructure mode. For example, as shown in Figure 4-13c (Example of ESS with general links), a network extended with GLK might consist of GLK STAs connected by IEEE Std 802.1Q bridged networks connected in some cases to an Internal Sublayer Service SAP provided by a GLK AP and in other cases provided by a GLK non-AP STA.
Figure 4-13c (Example of an ESS and extended networks with general links) shows a network consisting of three types of BSSs: a GLK infrastructure BSS (with only GLK STAs), an infrastructure BSS (with both GLK and non-GLK STAs), and an infrastructure BSS (containing only non-GLK STAs). The example ESS shown in the figure consists of the all the non-GLK non-AP STAs, the non-GLK AP and the portion of the GLK AP that has associated non-GLK non-AP STAs. In the ESS the portal that is connected to the DS does not show any additional connection, this is because the portal could be connected to any type of bridge, switch or LAN, hence no specific interconnection is shown. The general links shown in Figure 4-13c (Example of an ESS and extended networks with general links) are similar to those shown in Figure 4-13b and provide point-to-point links as described in 4.3.27.4.3. Also, shown in the figure is an example of the possible configuration of more than one 802.1Q MAC relay entity being attached to a GLK AP or GLK non-AP STA and the possible configuration of more than one GLK AP or GLK non-AP STA being attached to the same 802.1Q MAC relay entity. These configurations show the flexibility available with general links.
Note: IEEE Std 802.11 explicitly does not specify the details of the 802.1AC GLK convergence Function, the 802.1Q Media Independent Function, the Internal Sublayer Service to MAC-SAP Function, the 802.1Q MAC Relay Entity, and the LLC Sublayer. These entities are specified in other document such as: IEEE Std 802.1AC™-2016(Media Access Control (MAC) Service Definition) and IEEE Std 802.1Qbz™-2016 (Bridges and Bridged Networks — Amendment: 27 Enhancements to Bridging of 802.11 Media). These entities are shown with dashed outlines in the figure. Entities that IEEE Std 802.11 does specify are shown with solid outlines.
Figure 4-13c—Example of an ESS and extended network with general links
References:
[1] 11-17/0932r60932r7, “802.11ak Figs 4-13”, 11-17/0932r611-17/0932r7
[2]P802.11ak/D4.2, March 2017, “IEEE P802.11ak™/D4.2 Draft Standard Telecommunications and information exchange between systems – Local and metropolitan area networks Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 4: Enhancements For Transit Links Within Bridged Networks”,
Draft P802.11ak_D4.2
Submissionpage 1Joseph Levy (InterDigital)
[LJ1]Do we want to use the word “associated” here? Should we be using “attached” or some other word? We seem to have used the word “attached” in the BSS description text.
[LJ2]We agree that we should use “attached” for the bridge which is attached to the STA. Should we also use it for the network printer and computer? Above we are using “associated” – is there a different word that is better?